The present invention relates generally to structures for shielding against the penetration of radiated electromagnetic energy, and particularly to a joint structure and compression seam that is effective in minimizing leakage of electromagnetic energy at radio frequencies throughout the full frequency spectrum.
Classified information processing is generally performed on digital electronic equipment, such as computers and digitally controlled instrumentation. These devices transfer data between main frame units and input and output devices such as keyboard terminals and printers. Because of such transfer of data and information, there is a risk of disclosure because of the availability of sophisticated electronic surveillance devices. The effectiveness of these devices has increased dramatically in recent years. To meet such sophistication, one proposal has involved the placing of each piece of equipment in a shielded enclosure. However, with multiple pieces of equipment, the cost can be prohibitive if such a procedure is used.